This report updates information previously published regarding contamination of
Vapotherm® respiratory gas administration devices (Vapotherm, Inc., Stevensville, Maryland) with
Ralstonia spp. (1,2). The Food and
Drug Administration (FDA) has issued an updated Preliminary Public Health Notification, advising health-care providers
to use alternative devices until the source of the contamination has been identified.*

CDC continues to receive information regarding
Ralstonia spp. associated with Vapotherm use.
Twenty-nine institutions in 16 states have reported recovery of
Ralstonia spp. from Vapotherm devices and from approximately
40 pediatric patients. The majority of these cases appear to represent colonization, although one infection has been
reported to CDC and other cases remain under investigation. In addition, the recommended disinfecting protocol has
reportedly failed to eradicate Ralstonia spp. in three separate tests. Based on pulsed field gel electrophoresis analysis, isolates
from facilities in six states were determined closely related genetically, a finding that suggests intrinsic contamination of
some part of the device. Cultures of unused Vapotherm cartridges performed by two hospitals have yielded
Ralstonia spp. However, cultures of other unused cartridges from some of the same lots did not grow organisms in testing performed
by CDC and the cartridge manufacturer.

The source of contamination and the extent to which biofilm growth might be a contributing factor remain
unknown. Although the majority of organisms found in Vapotherm devices by CDC and reporting institutions have been
Ralstonia spp., other bacteria (e.g.,
Burkholderia cepacia, Alcaligenes xylosoxidans, Klebsiella pneumoniae, Proteus mirabilis,
and Sphingomonas paucimobilis) have been recovered from used cartridges or machines. CDC continues to work with
the manufacturer and FDA to determine the source of contamination of Vapotherm devices.

Ralstonia spp. are gram-negative bacteria found in the environment, primarily in water, soil, and on
plants; occasionally Ralstonia spp. are isolated from clinical samples (e.g., respiratory secretions of cystic fibrosis patients).
These organisms formerly were included in the genus
Pseudomonas or Burkholderia; however, DNA characterization has
revealed Ralstonia to be a distinct genus. The organism grows readily on media routinely used by clinical
microbiology laboratories (i.e., trypticase soy agar with 5% sheep blood or MacConkey agar)
(3). When both biochemical tests and automated identification systems are used,
Ralstonia spp. can be misidentified as
Burkholderia spp. or, less often, as non-aeruginosa
Pseudomonas spp. Signs and symptoms of an infection with
Ralstonia are similar to those observed in
other bacterial infections. Infections caused by
Ralstonia spp. should be treated on the basis of results of susceptibility
testing of the patient's isolate.

The current labeling for the Vapotherm device was cleared for marketing on August 18, 2004, with the indication,
"to add moisture to and to warm breathing gases for administration to patients." Other devices are marketed for this
general indication. FDA and CDC currently recommend use of alternative devices until the source of contamination can
be identified. A list of humidifiers can be found in the FDA 510(k) database, by entering "BTT" in the "Product
Code" field. Several heated humidifiers on the list have specifications similar to the Vapotherm device. Humidifiers will
require a gas source, connectors, and a patient interface (mask or nasal cannula) to make a complete system for administration
of breathing gas.

Clinicians who elect to use Vapotherm are encouraged to weigh the risk of potential bacterial contamination of
the device against the benefits Vapotherm might provide patients who require humidified oxygen therapy. Patients who
have been exposed to Vapotherm should be monitored for signs and symptoms of infection, and clinicians should
consider Ralstonia spp.infection in the differential diagnosis of exposed, symptomatic patients.

Hospitals should report cases of colonization or infection with
Ralstonia or related bacteria (gram-negative rods)
in patients exposed to Vapotherm directly to the device manufacturer and local or state public health departments
and CDC by telephone 800-893-0485. Adverse events associated with medical devices should be reported to
MedWatch, FDA's voluntary reporting program at
http://www.fda.gov/Medwatch/report.htm; by telephone, 800-FDA-1088;
by fax, 800-FDA-0178; or by mail, MedWatch, Food and Drug Administration, 5600 Fishers Lane, Rockville,
MD 20852-9787.

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Department of Health and Human Services. CDC is not responsible for the content
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the date of publication.

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